1. Field of the Invention
This invention broadly concerns a cutterhead and associated method for cutting weeds and other aquatic vegetation which cuts the weeds using angled teeth mounted to a rotating drum. More particularly, the cutterhead hereof provides a tearing action which also directs the cut vegetation and any sediment into a pump for removal to a remote site, utilizing an improved teeth arrangement employing double, back-to-back cutting teeth.
2. Description of the Prior Art
Many types of dredging operations encounter weeds or massed vegetation which has grown on sludge deposited in lagoons, in channels, or in other waters where removal is periodically required. Often the weeds or other aquatic vegetation represents an impediment to the removal of the underlying sludge, sand, silt or other deposits, because of the clogging effect of the vegetation. Cattails and plants with longs stems and gnarly roots often grow in sediment lagoons and in channels, and when the sediment is to be removed during dredging, these plants are especially tenacious and prone to cause clogging of the pumps. Moreover, they tend to wrap around many types of cutterheads typically used for clearing sediment. The entire dredging head must then be removed so that the plants can be cut away from the cutterhead. Thus, dredging in areas which have a large amount of aquatic vegetation represents one of the most difficult environs for sediment removal.
Many different types of apparatus have been used for cutting and removing aquatic vegetation. Exemplary devices of the prior art are shown in U.S. Pat. Nos. 669,820; 1,028,671; 1,795,003; 2,223,641; 2,486,275; 2,635,406; 2,702,975; 3,238,708; 3,407,577; 3,468,106; 3,653,192; 4,070,978; 4,095,545; 4,196,566; 4,205,507; 4,416,106; 4,248,033; 4,616,588; and 4,815,260. Unfortunately, none of these devices have solved the problems associated with wrapping of the plants around the cutterhead, nor have they adequately worked with the pumping system to remove the cut vegetation and the sediment to be removed.
An improvement to existing cutterheads is also shown in U.S. Pat. No. 5,481,856, the entire disclosure of which is incorporated herein by reference. However, the cutterhead of U.S. Pat. No. 5,481,856 utilized single, flat-sided teeth which broke, folded or clogged when attempting to dredge and cut particularly tough aquatic vegetation such as reeds, cattails or tussiks. Furthermore, the prior cutterheads have experienced deficiencies when cutting and harvesting aquatic vegetation at the surface of a body of water resulting from temporary loss of liquid and solid intake resulting in starvation of the pump. Such pump starvation causes loss of pump prime and the necessity to stop harvesting until the pump is reprimed.
Accordingly, there has developed a need for a weed-resistant cutterhead for use in aquatic environments, such as ponds, lakes, canals and waterways, which is capable of removing sediment and vegetation in plant-clogged areas.
There has also developed a real need for a cutterhead which is resistant to wrapping of long plant growth around the ends of a rotatable drum or reel.
There has also developed a need for a cutterhead which can direct the sediment and cut vegetation to an outlet port for pumping to a remote location.
There is a further need for a cutterhead having improved capabilities for harvesting vegetation at the surface of a body of water.